Method of making drain valves



March 6, 1934. B, MOLLBERG 1,949,613

METHOD OF MAKING DRAIN VALVES Original Filed April 13, 1951 FIG. IO

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BYRON MOLLBERG IN VEN TOR A TTORNE Y Fl G. l3

Patented Mar. 6, 1934 UNITED STATES METHOD OF MAKING DRAIN VALVES Byron Mollberg, St. Louis, Mo., assignor to Carter Carburetor Company, St. Louis, Mo., a corporation of Delaware Original application April 13, 1931, Serial No. 529,732. Patent No. 1,941,482, dated January 2, 1934. Divided and this application April 10,

1933, Serial No. 665,285

3 Claims. (01. 29-4571) The application is a division of my copending application Serial #529,732 filed April 3, 1931, issued as Patent No. 1,941,482 on January 2, 1934. The invention relates to a method of making the drain valve which is claimed as an article of manufacture in the above entitled application. In a broader aspect, the invention also relates to a method for forming screw threads.

The invention will be better understood upon reference to the accompanying drawing, in which:

Figure 1 shows a side elevation of the sheet metal blank from which the valve is made.

Figure 2 is an end view of the blank shown in Figure 1.

Figure 3 is a side elevation of the valve which is formed from the blank shown in Figure 1.

Figure 4 is an end View of the valve shown in Figure 3.

Figure 5 is an end view of the valve body.

Figure 6 is a side view of the valve body.

Figure 7 is a sectional view of the completed drain valve.

Figure 8 is an end view of the valve.

Figure 9 is a sectional view of the completed drain valve taken along the line 9-9 of Figure '7.

Figure 10 is a longitudinal sectional view of the valve body prior to assembly.

Figure 11 is a diagrammatic end view of a punch and die for forming the threads on the valve stem.

Figure 12 is a sectional view of the parts shown in Figure 11 taken along the line 12l2 of Figure 11.

Figure 13 is a diagrammatic end view of the finished punch and die for smoothing and sizing the thread after it has been formed in the dies shown in Figures 11 and 1 2.

The valve comprises only two parts: a stem member 1 or valve proper which is punched or blanked from sheet metal stock as indicated in Figures 1 and 2. The parts of the blank may be referred to as a handle 2 which may be of any suitable formation, a thread portion 3 which is to be threaded in any suitable manner, and a stem portion 1 which is to be headed over or upset to form a valve head 4, as indicated in Figures 3 and 7.

The blanks as shown in Figure 1 are punched from sheet metal stock in a manner which will be readily understood by those skilled in the art. After the blanks have been punched out or otherwise worked into the shape shown in Figure 1, the

completed drain thread portion 3 is threaded in any suitable manner, preferably by stamping in a threaded die as hereinafter described.

In order to form the valve head, the stem 1 is gripped in a suitable die and hammered, spun, or peened in such a manner as to swell the end to the form shown in Figures 3 and 1. It will be understood that during this operation the inner bevel or face 5 of the valve is directly supported on a surface of the die, so that it will be quite smooth when finished. In some cases where accurate work is necessary, the valve face 5 may be shaved or turned if desired.

The valve body 6 is formed in an automatic screw machine and comprises a hexagonal wrench portion '7, an integrally threaded portion 8, and a seat portion 9. The inside of the valve body is provided with a bore 10 extending longitudinally through the valve body concentric with the seat portion 9. The outer end of the bore 10 is threaded at 11 to receive the screw threaded portion 3 of the valve proper. It will be noted that the diameter of the bore 10 is substantially the same as the diameter of the valve head 4, so that the head can be slipped through the bore in assembly.

The valves are assembled by passing the'valve' head 4 through the bore 10 and threading the valve into the body by means of the threads 3 and 11. After assembly, the seat portion 9 is rolled or spun inwardly so that the diameter of its outside end is less than the diameter of the valve head 4. The tip end of the seat portion may be shaved, if desired, after the spinning operation, so that it will be perfectly true with the face of the valve 5, but this is not absolutely necessary as I prefer to form the valve of hard material and the valve body of soft material, so that the seat can be made to conform with the face of the valve by simply tightening the valve on the threads 3.

The threads 3 may be formed upon the valve body by any suitable means, but I prefer to form these threads in the manner shown in Figures 11 to 13. The reference numeral 12 indicates a die having a screw threaded portion 13 formed in the upper surface thereof. The upper edges of the die, as indicated at 14, are tapered so that a point will be formed at the tip end of each thread. The angle atwhich the surface 14 is to is to be out will be the controlling factors, but, generally speaking, an angle of fifteen degrees from the horizontal will give good results.

The punch 15 has a lower face which is threaded, as indicated at 16, in such a manner as to form a continuation of the threads 13 of the die. The walls or edges 1'? are also tapered upwardly, as indicated, so as to meet the edges 14 at an angle and thereby form a cutting edge. The diameter of the threads 13 and 16 should be slightly larger than the size to which it is proposed to finish the threads 3 of the valve, and the blank should be made of sufficiently large size so that a complete thread of the proposed larger type may be cut from it.

In Figures 11 and 12, the blank is indicated by the dotted lines 3, and when the punch and die are brought together, the outer edges of the blank will be cut off in the form of the wedgeshaped clippings 19. It will be understood that the angle between the surfaces 14 and 17 is calculated to be just sufficient to permit the slippage of the shaving away from the blank as the punch and die come together. When the punch comes in contact with the die, the shavings will break away entirely, leaving a somewhat rough place on the thread where they break away.

In Figure 13, the reference numeral 20 indicates a die and 21 a punch having a face identical with the face of the die. The face of the punch and die is screw threaded, as indicated at 22, and the thread diameter is the same as the desired thread diameter in the finished product. In Figure 13, the blank to be threaded is indicated by the reference numeral 3 corresponding with the threaded portion 3 in Figures 1 and 3. In this die, the blank is held with its flat sides parallel to the direction of movement of the punch, as shown in Figure 13, and when the punch is brought down, the screw threaded portions 22 serve to smooth the thread surface of the blank and at the same time to reduce the thread diameter to the desired size.

It will be obvious that this method of thread forming may be used for forming threads on articles other than the valve herein shown and described, and it will also be understood that the valve may be used as a drain valve for automotive or house heating radiators, for draining crank cases, and for many other purposes.

In operation, the valve may be closed by screwing the valve head outwardly until the valve face 5 contacts with the seat portion 9, and it may be opened by screwing in the opposite direction. It will be noted that the fluid passageways through the valve lie on opposite sides of the flat valve member 1 which, of course, does not conform to the circular cross section of the bore 10 or the threads 11.

I claim:

1, The method of making valves which comprises forming from sheet metal stock a blank having a portion at one end suitable for a handle, a comparatively long and slender stem at the other end containing sufiicient metal for forming into a valve head, and an intermediate portion having a greater width than the thickness of the sheet metal; forming threads on said intermediate portion, and upsetting the end of said stem to form a valve head.

2. The method of manufacturing valves which comprises forming from sheet metal stock a blank having a portion of greater width than the thickness of the blank and adapted to be threaded, forming a stem portion of less width than said portion which is adapted to be threaded but adjacent thereto, forming threads on said portion which is adapted to be threaded and upsetting the end of said stern portion to form a valve head of circular cross section.

3. The method of manufacturing valves which comprises forming a body member having a passageway therethrough and threads in said passageway, forming on the end of said body member a cylindrical skirt or flange coaxial with said passageway, forming a valve member with a head portion adapted to be inserted in said passageway and a threaded portion separated from said head portion by a stem portion for engagement with the threads of the body member, said stem portion being of smaller cross section than said head and threaded portions, and rolling or spinning said skirt in such a manner as to reduce its diameter to such a point that it serves to form a valve seat for the head of said valve.

B. MOLLBERG. 

